Two large bomb blasts rocked the Ritz-Carlton and JW Marriott hotels in the Indonesian capital on Friday, killing nine, Indonesia's top security official said, in the first such attack in the Southeast Asian nation since 2005.

Several foreigners were also among the dead. Nearly 50 people were also wounded in the twin explosions early morning in Jakarta, Agence France-Presse said.

The streets outside the two hotels, which sit adjacent to each other in the Mega Kuningan business district in central Jakarta were covered in shattered glass and debris.

The facade of the Ritz-Carlton was ripped off after an explosion in the restaurant while people were having breakfast, police said.

Authorities were acting on the assumption that the bombing was carried out by Muslim extremists, said a senior counterterrorism official, the Wall Street Journal said.

Chief security minister Widodo AS said nine people were killed and 41 wounded. He said the blasts were caused by high-level explosives.

Four foreigners were dead, The Associated Press and local Metro TV said. The blasts may have come from the front and the basement of the hotels, the Antara news agency said.

Another explosion was reported at a toll-road gate in north Jakarta around three hours later, but it isn't immediately clear if the incidents were related.

Among those killed was PT Holcim Indonesia's (SMCB.JK) chief executive Timothy Mackay. He was at the Marriott, a company official said, and died from his injuries in hospital.

A New Zealander, an Australian and a South Korean were among the injured, reports said.

The first explosion took place around 7:40 a.m. local time (0045 GMT) with the second taking place minutes later.

"I heard two sounds like 'boom, boom' coming from the Marriott and the Ritz-Carlton. Then I saw people running out," security guard Eko Susanto told AFP.

Police had sealed off the area near the Ritz-Carlton and the JW Marriott in the Mega Kuningan district. "I heard at least three explosions and now white smoke is billowing," a fund manager at a foreign securities company told Dow Jones Newswires by phone.

Indonesia hasn't suffered a major terrorist attack since the 2005 bombings of seafood restaurants on the resort island of Bali. The JW Marriott was the target of an earlier bombing in 2003, in which 12 people died.

That blast was blamed on regional terror group Jemaah Islamiyah, also blamed for the 2002 Bali bombings that killed 202 people.

"I saw some people being carried into a Mercedes. There was a lot of them in there, they were having trouble closing the doors," a witness, who gave her name as Mery, told ElShinta radio.

Several embassies and a number of leading financial institutions have offices in the area. The Manchester United soccer team is scheduled to stay at the Ritz-Carlton hotel on their Southeast Asian tour, local reports said.

President Susilo Bambang Yudhoyono will deliver a statement on the bombing soon, the Detikcom news site said.

-By I Made Sentana; Dow Jones Newswires; 62-21 39831277; I-Made.Sentana@dowjones.com